Many of you probably jumped on Borderlands 2 when it came out, and noticed a certain lack of pony references in it's internet humor filled dialogue. There were a few that "could" have been (the diamond pony for example), but nothing specific.
It looks like they were waiting for the DLC before really going nuts with it! Introducing the Mechromancer's skill tree, filled with pony talents.
Head on over to the skill calculator to check it out, or down past the break for screenshots of all of them courtesy of the first submitters, Skai and Dan Strauss